[Help-smalltalk] [bug] LargePositiveInteger asFloat: does not round correctly

[Nicolas Cellier]

Issue status update for 
http://smalltalk.gnu.org/node/309
Post a follow up: 
http://smalltalk.gnu.org/project/comments/add/309

Project:      GNU Smalltalk
Version:      <none>
Component:    Base classes
Category:     bug reports
Priority:     normal
Assigned to:  Unassigned
Reported by:  nice
Updated by:   nice
Status:       active

Paolo, the simplification you made are great!
But you just swapped the lowBit test...

Example:

self assert: ((1 bitShift: 53+100) + (1 bitShift: 100) + 1) asFloatD
truncated lowBit = 102.

Number of truncated bits is 101.
Carry is 1.
Truncated mantissa candidate is even (1 bitShift: 52).
But there are other trailing bits behind the carry (self lowBit <
nTruncatedBits), so the truncated part > 0.5 ulp, so the mantissa must
be rounded upper.

Please correct.
Cheers